A honeycomb is a mass of hexagonal prismatic wax cells built by honey bees in their nests to contain their larvae and stores of honey and pollen. Beekeepers may remove the entire honeycomb to harvest honey. Honey bees consume about 8.4 lb of honey to secrete 1 lb of wax, so it makes economic sense to return the wax to the hive after harvesting the honey. The structure of the comb may be left intact when honey is extracted from it by uncapping and spinning in a centrifugal machine—the honey extractor. If the honeycomb is too worn out, the wax can be reused in a number of ways, including making sheets of comb foundation with hexagonal pattern; such foundation sheets allow the bees to build the comb with less effort, the hexagonal pattern of worker-sized cell bases discourages the bees from building the larger drone cells. Fresh, new comb is sometimes sold and used intact as comb honey if the honey is being spread on bread rather than used in cooking or as a sweetener. Broodcomb becomes dark over time, because of the cocoons embedded in the cells and the tracking of many feet, called travel stain by beekeepers when seen on frames of comb honey.
Honeycomb in the "supers" that are not used for brood stays light-colored. Numerous wasps Polistinae and Vespinae, construct hexagonal prism-packed combs made of paper instead of wax. However, the term "honeycomb" is not used for such structures; the axes of honeycomb cells are always quasihorizontal, the nonangled rows of honeycomb cells are always horizontally aligned. Thus, each cell has two vertically oriented walls, with the upper and lower parts of the cells composed of two angled walls; the open end of a cell is referred to as the top of the cell, while the opposite end is called the bottom. The cells slope upwards, between 9 and 14°, towards the open ends. Two possible explanations exist as to why honeycomb is composed of hexagons, rather than any other shape. First, the hexagonal tiling creates a partition with equal-sized cells, while minimizing the total perimeter of the cells. Known in geometry as the honeycomb conjecture, this was given by Jan Brożek and proved much by Thomas Hales.
Thus, a hexagonal structure uses the least material to create a lattice of cells within a given volume. A second reason, given by D'Arcy Wentworth Thompson, is that the shape results from the process of individual bees putting cells together: somewhat analogous to the boundary shapes created in a field of soap bubbles. In support of this, he notes that queen cells, which are constructed singly, are irregular and lumpy with no apparent attempt at efficiency; the closed ends of the honeycomb cells are an example of geometric efficiency, albeit three-dimensional. The ends are trihedral sections of rhombic dodecahedra, with the dihedral angles of all adjacent surfaces measuring 120°, the angle that minimizes surface area for a given volume; the shape of the cells is such that two opposing honeycomb layers nest into each other, with each facet of the closed ends being shared by opposing cells. Individual cells do not show this geometric perfection: in a regular comb, deviations of a few percent from the "perfect" hexagonal shape occur.
In transition zones between the larger cells of drone comb and the smaller cells of worker comb, or when the bees encounter obstacles, the shapes are distorted. Cells are angled up about 13° from horizontal to prevent honey from dripping out. In 1965, László Fejes Tóth discovered the trihedral pyramidal shape used by the honeybee is not the theoretically optimal three-dimensional geometry. A cell end composed of two hexagons and two smaller rhombuses would be.035% more efficient. This difference is too minute to measure on an actual honeycomb, irrelevant to the hive economy in terms of efficient use of wax, considering wild comb varies from any mathematical notion of "ideal" geometry. Bees used their antennae and legs to manipulate the wax during comb construction, while warming the wax. During the construction of hexagonal cells, wax temperature is between 33.6 and 37.6°C, well below the 40°C temperature at which wax is assumed to be liquid for initiating new comb construction. The body temperature of bees is a factor for regulating an ideal wax temperature for building the comb.
Honeycomb structure Wax foundation Hive frame Jan Dzierzon
Southeast Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China and Japan, east of India, west of Papua New Guinea, north of Australia. Southeast Asia is bordered to the north by East Asia, to the west by South Asia and the Bay of Bengal, to the east by Oceania and the Pacific Ocean, to the south by Australia and the Indian Ocean; the region is the only part of Asia that lies within the Southern Hemisphere, although the majority of it is in the Northern Hemisphere. In contemporary definition, Southeast Asia consists of two geographic regions: Mainland Southeast Asia known as Indochina, comprising parts of Northeast India, Laos, Thailand and West Malaysia. Maritime Southeast Asia known as Nusantara, the East Indies and Malay Archipelago, comprises the Andaman and Nicobar Islands of India, East Malaysia, the Philippines, East Timor, Christmas Island, the Cocos Islands. Taiwan is included in this grouping by many anthropologists; the region lies near the intersection of geological plates, with both heavy seismic and volcanic activities.
The Sunda Plate is the main plate of the region, featuring all Southeast Asian countries except Myanmar, northern Thailand, northern Laos, northern Vietnam, northern Luzon of the Philippines. The mountain ranges in Myanmar and peninsular Malaysia are part of the Alpide belt, while the islands of the Philippines are part of the Pacific Ring of Fire. Both seismic belts meet in Indonesia, causing the region to have high occurrences of earthquakes and volcanic eruptions. Southeast Asia covers about 4.5 million km2, 10.5% of Asia or 3% of earth's total land area. Its total population is about 8.5 % of the world's population. It is the third most populous geographical region in the world after East Asia; the region is culturally and ethnically diverse, with hundreds of languages spoken by different ethnic groups. Ten countries in the region are members of ASEAN, a regional organization established for economic, military and cultural integration amongst its members; the region, together with part of South Asia, was well known by Europeans as the East Indies or the Indies until the 20th century.
Chinese sources referred the region as 南洋, which means the "Southern Ocean." The mainland section of Southeast Asia was referred to as Indochina by European geographers due to its location between China and the Indian subcontinent and its having cultural influences from both neighboring regions. In the 20th century, the term became more restricted to territories of the former French Indochina; the maritime section of Southeast Asia is known as the Malay Archipelago, a term derived from the European concept of a Malay race. Another term for Maritime Southeast Asia is Insulindia, used to describe the region between Indochina and Australasia; the term "Southeast Asia" was first used in 1839 by American pastor Howard Malcolm in his book Travels in South-Eastern Asia. Malcolm only included the Mainland section and excluded the Maritime section in his definition of Southeast Asia; the term was used in the midst of World War II by the Allies, through the formation of South East Asia Command in 1943.
SEAC popularised the use of the term "Southeast Asia," although what constituted Southeast Asia was not fixed. However, by the late 1970s, a standard usage of the term "Southeast Asia" and the territories it encompasses had emerged. Although from a cultural or linguistic perspective the definitions of "Southeast Asia" may vary, the most common definitions nowadays include the area represented by the countries listed below. Ten of the eleven states of Southeast Asia are members of the Association of Southeast Asian Nations, while East Timor is an observer state. Papua New Guinea has stated that it might join ASEAN, is an observer. Sovereignty issues exist over some territories in the South China Sea; some southern parts of Mainland China, as well as Hong Kong and Taiwan, are considered as part of Southeast Asia by some authors. * Administrative centre in Putrajaya. Southeast Asia is geographically divided into two subregions, namely Mainland Southeast Asia and Maritime Southeast Asia. Mainland Southeast Asia includes: Maritime Southeast Asia includes: The Andaman and Nicobar Islands of India are geographically considered part of Maritime Southeast Asia.
Eastern Bangladesh and Northeast India have strong cultural ties with Southeast Asia and sometimes considered both South Asian and Southeast Asian. Sri Lanka has on some occasions been considered a part of Southeast Asia because of its cultural ties to mainland Southeast Asia; the rest of the island of New Guinea, not part of Indonesia, Papua New Guinea, is sometimes included, so are Palau and the Northern Mariana Islands, which were all part of the Spanish East Indies with strong cultural and linguistic ties to the region the Philippines. The eastern half of Indonesia and East Timor are considered to be biogeographically part of Oceania due to its distinctive faunal features. New Guinea and its surrounding islands are geologically considered as a part of Australian continent, connected via the Sahul Shelf; the region
Honey is a sweet, viscous food substance produced by bees and some related insects. Bees produce honey from the sugary secretions of plants or from secretions of other insects, by regurgitation, enzymatic activity, water evaporation. Bees store honey in wax structures called a honeycomb; the variety of honey produced by honey bees is the best-known, due to its worldwide commercial production and human consumption. Honey is collected from wild bee colonies, or from hives of domesticated bees, a practice known as beekeeping or apiculture. Honey gets its sweetness from the monosaccharides fructose and glucose, has about the same relative sweetness as sucrose, it has attractive chemical properties for a distinctive flavor when used as a sweetener. Most microorganisms do not grow in honey, so sealed honey does not spoil after thousands of years. Honey provides 46 calories in a serving of one tablespoon. Honey is regarded as safe. Honey use and production have a long and varied history as an ancient activity.
Several cave paintings in Cuevas de la Araña, depict humans foraging for honey at least 8,000 years ago. Honey is produced by bees collecting nectar for use as sugars consumed to support metabolism of muscle activity during foraging or to be stored as a long-term food supply. During foraging, bees access part of the nectar collected to support metabolic activity of flight muscles, with the majority of collected nectar destined for regurgitation and storage as honey. In cold weather or when other food sources are scarce and larval bees use stored honey as food. By contriving for bee swarms to nest in human-made hives, people have been able to semidomesticate the insects and harvest excess honey. In the hive or in a wild nest, the three types of bees are: a single female queen bee a seasonally variable number of male drone bees to fertilize new queens 20,000 to 40,000 female worker beesLeaving the hive, a foraging bee collects sugar-rich flower nectar, sucking it through its proboscis and placing it in its proventriculus, which lies just dorsal to its food stomach.
The honey stomach holds about 40 mg of nectar, or 50% of the bee's unloaded weight, which can require over a thousand flowers and more than an hour to fill. The nectar begins with a water content of 70 to 80%. Salivary enzymes and proteins from the bee's hypopharyngeal gland are added to the nectar to begin breaking down the sugars, raising the water content slightly; the forager bees return to the hive, where they regurgitate and transfer nectar to the hive bees. The hive bees use their honey stomachs to ingest and regurgitate the nectar, forming bubbles between their mandibles until it is digested; the bubbles create a large surface area per volume and a portion of the water is removed through evaporation. Bee digestive enzymes hydrolyze sucrose to a mixture of glucose and fructose, break down other starches and proteins, increasing the acidity; the bees work together as a group with the regurgitation and digestion for as long as 20 minutes, passing the nectar from one bee to the next, until the product reaches the honeycombs in storage quality.
It is placed in honeycomb cells and left unsealed while still high in water content and natural yeasts which, would cause the sugars in the newly formed honey to ferment. Bees are some of the few insects that can generate large amounts of body heat, thus the hive bees regulate the hive temperature, either heating with their bodies or cooling with water evaporation, to maintain a constant temperature in the honey-storage areas around 35 °C; the process continues as hive bees flutter their wings to circulate air and evaporate water from the honey to a content around 18%, raising the sugar concentration beyond the saturation point and preventing fermentation. The bees cap the cells with wax to seal them; as removed from the hive by a beekeeper, honey has a long shelf life and will not ferment if properly sealed. Another source of honey is from a number of wasp species, such as Brachygastra lecheguana and Brachygastra mellifica, which are found in South and Central America; these species are known to produce honey.
Some wasps, such as Polistes versicolor consume honey themselves, alternating between feeding on pollen in the middle of their lifecycles and feeding on honey, which can better provide for their energy needs. Honey is collected from domesticated beehives. On average, a hive will produce about 65 pounds of honey per year. Wild bee nests are sometimes located by following a honeyguide bird. To safely collect honey from a hive, beekeepers pacify the bees using a bee smoker; the smoke triggers a feeding instinct, making them less aggressive and the smoke obscures the pheromones the bees use to communicate. The honeycomb is removed from the hive and the honey may be extracted from that, either by crushing or by using a honey extractor; the honey is usually filtered to remove beeswax and other debris. Before the invention of removable frames, bee colonies were sacrificed to conduct the harvest; the harvester would replace the entire colony the next spring. Since the invention of removable frames, the principles of husbandry led most beekeepers to ensure that their bees have enough stores to survive the winter, either by leaving some honey in the beehive or by providing the colony with a honey substitute such as sugar water or crystalline sugar.
The amount o
Laos the Lao People's Democratic Republic referred to by its colloquial name of Muang Lao, is a socialist state and the only landlocked country in Southeast Asia. Located at the heart of the Indochinese peninsula, Laos is bordered by Myanmar and China to the northwest, Vietnam to the east, Cambodia to the southwest, Thailand to the west and southwest. Present-day Laos traces its historic and cultural identity to the kingdom of Lan Xang Hom Khao, which existed for four centuries as one of the largest kingdoms in Southeast Asia. Due to Lan Xang's central geographical location in Southeast Asia, the kingdom became a popular hub for overland trade, becoming wealthy economically as well as culturally. After a period of internal conflict, Lan Xang broke off into three separate kingdoms—Luang Phrabang and Champasak. In 1893, it became a French protectorate, with the three territories uniting to form what is now known as the country of Laos, it gained independence in 1945 after Japanese occupation, but was recolonised by France until it won autonomy in 1949.
Laos became independent with a constitutional monarchy under Sisavang Vong. Shortly after independence, a long civil war began, which saw the communist resistance, supported by the Soviet Union, fight against, the monarchy and a number of military dictatorships, supported by the United States. After the Vietnam War ended in 1975, the Communist Pathet Lao movement came to power, seeing the end to the civil war. During the first years of Communist rule, Laos was dependent on military and economic aid supported by the Soviet Union until its dissolution in 1991. In 2018, the country had the fourth highest GDP per capita in Indochina, after Singapore and Thailand. In the same year, the country ranked 139th on the Human Development Index, indicating medium development. Laos is a member of the Asia-Pacific Trade Agreement, Association of Southeast Asian Nations, East Asia Summit and La Francophonie. Laos applied for membership of the World Trade Organization in 1997, it is a one-party socialist republic espousing Marxism–Leninism governed by the Lao People's Revolutionary Party.
The capital and largest city is Vientiane. Other major cities include Luang Prabang and Pakse; the official language is Lao. Laos is a multi-ethnic country, with the politically and culturally dominant Lao people making up about 55 percent of the population in the lowlands. Mon-Khmer groups, the Hmong and other indigenous hill tribes, accounting for 45 percent of the population, live in the foothills and mountains. Laos's strategies for development are based on generating electricity from its rivers and selling the power to its neighbours, namely Thailand and Vietnam, as well as its initiative to become a "land-linked" nation, shown by the construction of four new railways connecting Laos to its neighbours. Laos has been referred to as one of East Asia and Pacific's Fastest Growing Economies by the World Bank, with annual GDP growth averaging 7.8% for the past decade. The English word Laos was coined by the French, who united the three Lao kingdoms in French Indochina in 1893 and named the country as the plural of the dominant and most common ethnic group, which are the Lao people.
In the Lao language, the country's name is "Muang Lao" or "Pathet Lao", both mean "Lao Country". An ancient human skull was recovered from the Tam Pa Ling Cave in the Annamite Mountains in northern Laos. Stone artifacts including Hoabinhian types have been found at sites dating to the Late Pleistocene in northern Laos. Archaeological evidence suggests agriculturist society developed during the 4th millennium BC. Burial jars and other kinds of sepulchers suggest a complex society in which bronze objects appeared around 1500 BC, iron tools were known from 700 BC; the proto-historic period is characterised by contact with Indian civilisations. According to linguistic and other historical evidence, Tai-speaking tribes migrated southwestward to the modern territories of Laos and Thailand from Guangxi sometime between the 8th–10th centuries. Laos traces its history to the kingdom of Lan Xang, founded in the 14th century by a Lao prince Fa Ngum, with 10,000 Khmer troops, took over Vientiane. Ngum was descended from a long line of Lao kings.
He made Theravada Buddhism Lan Xang prospered. Within 20 years of its formation, the kingdom expanded eastward to Champa and along the Annamite mountains in Vietnam, his ministers, unable to tolerate his ruthlessness, forced him into exile to the present-day Thai province of Nan in 1373, where he died. Fa Ngum's eldest son, Oun Heuan, ascended to the throne under the name Samsenthai and reigned for 43 years. Lan Xang became an important trade centre during Samsenthai's reign, but after his death in 1421 it collapsed into warring factions for 100 years. In 1520, Photisarath came to the throne and moved the capital from Luang Prabang to Vientiane to avoid a Burmese invasion. Setthathirat became king in 1548, after his father was killed, ordered the construction of what became the symbol of Laos, That Luang. Setthathirat disappeared in the mountains on his way back from a military expedition into Cambodia and Lan Xang began to decline, it was not until 1637, when Sou
The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period 145 million years ago to the beginning of the Paleogene Period 66 mya. It is the last period of the Mesozoic Era, the longest period of the Phanerozoic Eon; the Cretaceous Period is abbreviated K, for its German translation Kreide. The Cretaceous was a period with a warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas; these oceans and seas were populated with now-extinct marine reptiles and rudists, while dinosaurs continued to dominate on land. During this time, new groups of mammals and birds, as well as flowering plants, appeared; the Cretaceous ended with the Cretaceous–Paleogene extinction event, a large mass extinction in which many groups, including non-avian dinosaurs and large marine reptiles died out. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary, a geologic signature associated with the mass extinction which lies between the Mesozoic and Cenozoic eras.
The Cretaceous as a separate period was first defined by Belgian geologist Jean d'Omalius d'Halloy in 1822, using strata in the Paris Basin and named for the extensive beds of chalk, found in the upper Cretaceous of Western Europe. The name Cretaceous was derived from Latin creta; the Cretaceous is divided into Early and Late Cretaceous epochs, or Lower and Upper Cretaceous series. In older literature the Cretaceous is sometimes divided into three series: Neocomian and Senonian. A subdivision in eleven stages, all originating from European stratigraphy, is now used worldwide. In many parts of the world, alternative local subdivisions are still in use; as with other older geologic periods, the rock beds of the Cretaceous are well identified but the exact age of the system's base is uncertain by a few million years. No great extinction or burst of diversity separates the Cretaceous from the Jurassic. However, the top of the system is defined, being placed at an iridium-rich layer found worldwide, believed to be associated with the Chicxulub impact crater, with its boundaries circumscribing parts of the Yucatán Peninsula and into the Gulf of Mexico.
This layer has been dated at 66.043 Ma. A 140 Ma age for the Jurassic-Cretaceous boundary instead of the accepted 145 Ma was proposed in 2014 based on a stratigraphic study of Vaca Muerta Formation in Neuquén Basin, Argentina. Víctor Ramos, one of the authors of the study proposing the 140 Ma boundary age sees the study as a "first step" toward formally changing the age in the International Union of Geological Sciences. From youngest to oldest, the subdivisions of the Cretaceous period are: Late Cretaceous Maastrichtian – Campanian – Santonian – Coniacian – Turonian – Cenomanian – Early Cretaceous Albian – Aptian – Barremian – Hauterivian – Valanginian – Berriasian – The high sea level and warm climate of the Cretaceous meant large areas of the continents were covered by warm, shallow seas, providing habitat for many marine organisms; the Cretaceous was named for the extensive chalk deposits of this age in Europe, but in many parts of the world, the deposits from the Cretaceous are of marine limestone, a rock type, formed under warm, shallow marine circumstances.
Due to the high sea level, there was extensive space for such sedimentation. Because of the young age and great thickness of the system, Cretaceous rocks are evident in many areas worldwide. Chalk is a rock type characteristic for the Cretaceous, it consists of coccoliths, microscopically small calcite skeletons of coccolithophores, a type of algae that prospered in the Cretaceous seas. In northwestern Europe, chalk deposits from the Upper Cretaceous are characteristic for the Chalk Group, which forms the white cliffs of Dover on the south coast of England and similar cliffs on the French Normandian coast; the group is found in England, northern France, the low countries, northern Germany, Denmark and in the subsurface of the southern part of the North Sea. Chalk is not consolidated and the Chalk Group still consists of loose sediments in many places; the group has other limestones and arenites. Among the fossils it contains are sea urchins, belemnites and sea reptiles such as Mosasaurus. In southern Europe, the Cretaceous is a marine system consisting of competent limestone beds or incompetent marls.
Because the Alpine mountain chains did not yet exist in the Cretaceous, these deposits formed on the southern edge of the European continental shelf, at the margin of the Tethys Ocean. Stagnation of deep sea currents in middle Cretaceous times caused anoxic conditions in the sea water leaving the deposited organic matter undecomposed. Half the worlds petroleum reserves were laid down at this time in the anoxic conditions of what would become the Persian Gulf and the Gulf of Mexico. In many places around the world, dark anoxic shales were formed during this interval; these shales are an important source rock for oil and gas, for example in the subsurface of the North Sea. During th
Bears are carnivoran mammals of the family Ursidae. They are classified as doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout the Northern Hemisphere and in the Southern Hemisphere. Bears are found on the continents of North America, South America and Asia. Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, short tails. While the polar bear is carnivorous, the giant panda feeds entirely on bamboo, the remaining six species are omnivorous with varied diets. With the exception of courting individuals and mothers with their young, bears are solitary animals, they may have an excellent sense of smell. Despite their heavy build and awkward gait, they are adept runners and swimmers. Bears use shelters, such as logs, as their dens. Bears have been hunted since prehistoric times for their fur. With their powerful physical presence, they play a prominent role in the arts and other cultural aspects of various human societies.
In modern times, bears have come under pressure through encroachment on their habitats and illegal trade in bear parts, including the Asian bile bear market. The IUCN lists six bear species as vulnerable or endangered, least concern species, such as the brown bear, are at risk of extirpation in certain countries; the poaching and international trade of these most threatened populations are prohibited, but still ongoing. The English word "bear" comes from Old English bera and belongs to a family of names for the bear in Germanic languages, such as Swedish björn used as a first name; this form is conventionally said to be related to a Proto-Indo-European word for "brown", so that "bear" would mean "the brown one". However, Ringe notes that while this etymology is semantically plausible, a word meaning "brown" of this form cannot be found in Proto-Indo-European, he suggests instead that "bear" is from the Proto-Indo-European word *ǵʰwḗr- ~ *ǵʰwér "wild animal". This terminology for the animal originated as a taboo avoidance term: proto-Germanic tribes replaced their original word for bear—arkto—with this euphemistic expression out of fear that speaking the animal's true name might cause it to appear.
According to author Ralph Keyes, this is the oldest known euphemism. Bear taxon names such as Arctoidea and Helarctos come from the ancient Greek word ἄρκτος, meaning bear, as do the names "arctic" and "antarctic", from the constellation Ursa Major, the "Great Bear", prominent in the northern sky. Bear taxon names such as Ursidae and Ursus come from he-bear/she-bear; the female first name "Ursula" derived from a Christian saint's name, means "little she-bear". In Switzerland, the male first name "Urs" is popular, while the name of the canton and city of Bern is derived from Bär, German for bear; the Germanic name Bernard means "bear-brave", "bear-hardy", or "bold bear". The Old English name Beowulf is a kenning; the family Ursidae is one of nine families in the suborder Caniformia, or "doglike" carnivorans, within the order Carnivora. Bears' closest living relatives are the pinnipeds and musteloids. Modern bears comprise eight species in three subfamilies: Ailuropodinae and Ursinae. Nuclear chromosome analysis show that the karyotype of the six ursine bears is nearly identical, with each having 74 chromosomes, whereas the giant panda has 42 chromosomes and the spectacled bear 52.
These smaller numbers can be explained by the fusing of some chromosomes, the banding patterns on these match those of the ursine species, but differ from those of procyonids, which supports the inclusion of these two species in Ursidae rather than in Procyonidae, where they had been placed by some earlier authorities. The earliest members of Ursidae belong to the extinct subfamily Amphicynodontinae, including Parictis and the younger Allocyon, both from North America; these animals looked different from today's bears, being small and raccoon-like in overall appearance, with diets more similar to that of a badger. Parictis does not appear in Africa until the Miocene, it is unclear whether late-Eocene ursids were present in Eurasia, although faunal exchange across the Bering land bridge may have been possible during a major sea level low stand as early as the late Eocene and continuing into the early Oligocene. European genera morphologically similar to Allocyon, to the much younger American Kolponomos, are known from the Oligocene, including Amphicticeps and Amphicynodon.
There has been various morphological evidence linking amphicynodontines with pinnipeds, as both groups were semi-aquatic, otter-like mammals. In addition to the support of the pinniped–amphicynodontine clade, other morphological and some molecular evidence supports bears being the closet living relatives to pinnipeds; the raccoon-sized, dog-like Cephalogale is the oldest-known member of the subfamily Hemicyoninae, which first appeared during the middle Oligocene in Eurasia about 30 Mya
Bangladesh the People's Republic of Bangladesh, is a sovereign country in South Asia. It shares land borders with Myanmar; the country's maritime territory in the Bay of Bengal is equal to the size of its land area. Bangladesh is the world's eighth most populous country as well as its most densely-populated, to the exclusion of small island nations and city-states. Dhaka is largest city, followed by Chittagong, which has the country's largest port. Bangladesh forms the largest and easternmost part of the Bengal region. Bangladeshis include people from a range of ethnic religions. Bengalis, who speak the official Bengali language, make up 98% of the population; the politically dominant Bengali Muslims make the nation the world's third largest Muslim-majority country. Islam is the official religion of Bangladesh. Most of Bangladesh is covered by the largest delta on Earth; the country has 8,046 km of inland waterways. Highlands with evergreen forests are found in the northeastern and southeastern regions of the country.
Bangladesh has a coral reef. The longest unbroken natural sea beach of the world, Cox's Bazar Beach, is located in the southeast, it is home to the Sundarbans, the largest mangrove forest in the world. The country's biodiversity includes a vast array of plant and wildlife, including endangered Bengal tigers, the national animal; the Greeks and Romans identified the region as Gangaridai, a powerful kingdom of the historical Indian subcontinent, in the 3rd century BCE. Archaeological research has unearthed several ancient cities in Bangladesh, which enjoyed international trade links for millennia; the Bengal Sultanate and Mughal Bengal transformed the region into a cosmopolitan Islamic imperial power between the 14th and 18th centuries. The region was home to many principalities; as the Mughal Empire's wealthiest province, Bangladesh as part of the Bengal Subah was worth 12% of the world's GDP, larger than the entirety of western Europe. It was a notable center of the global muslin and silk trade.
As part of British India, the region was influenced by the Bengali renaissance and played an important role in anti-colonial movements. The Partition of British India made East Bengal a part of the Dominion of Pakistan; the region witnessed the Bengali Language Movement in 1952 and the Bangladesh Liberation War in 1971. After independence was achieved, a parliamentary republic was established. A presidential government was in place between 1975 and 1990, followed by a return to parliamentary democracy; the country continues to face challenges in the areas of poverty, education and corruption. Bangladesh is a developing nation. Listed as one of the Next Eleven, its economy ranks 43rd in terms of nominal gross domestic product and 29th in terms of purchasing power parity, it is one of the largest textile exporters in the world. Its major trading partners are the European Union, the United States, India, Japan and Singapore. With its strategically vital location between South and Southeast Asia, Bangladesh is an important promoter of regional connectivity and cooperation.
It is a founding member of SAARC, BIMSTEC, the Bangladesh-China-India-Myanmar Forum for Regional Cooperation and the Bangladesh Bhutan India Nepal Initiative. It is a member of the Organisation of Islamic Cooperation, Commonwealth of Nations, the Developing 8 Countries, the OIC, the Indian-Ocean Rim Association, the Non Aligned Movement, the Group of 77 and the World Trade Organization. Bangladesh is one of the largest contributors to United Nations peacekeeping forces; the etymology of Bangladesh can be traced to the early 20th century, when Bengali patriotic songs, such as Namo Namo Namo Bangladesh Momo by Kazi Nazrul Islam and Aaji Bangladesher Hridoy by Rabindranath Tagore, used the term. The term Bangladesh was written as two words, Bangla Desh, in the past. Starting in the 1950s, Bengali nationalists used the term in political rallies in East Pakistan; the term Bangla is a major name for both the Bengali language. The earliest known usage of the term is the Nesari plate in 805 AD; the term Vangaladesa is found in 11th-century South Indian records.
The term gained official status during the Sultanate of Bengal in the 14th century. Shamsuddin Ilyas Shah proclaimed himself as the first "Shah of Bangala" in 1342; the word Bangla became the most common name for the region during the Islamic period. The Portuguese referred to the region as Bengala in the 16th century; the origins of the term Bangla are unclear, with theories pointing to a Bronze Age proto-Dravidian tribe, the Austric word "Bonga", the Iron Age Vanga Kingdom. The Indo-Aryan suffix Desh is derived from the Sanskrit word deśha, which means "land" or "country". Hence, the name Bangladesh means "Land of Bengal" or "Country of Bengal". Stone Age tools found in Bangladesh indicate human habitation for over 20,000 years, remnants of Copper Age settlements date back 4,000 years. Ancient Bengal was settled by Austroasiatics, Tibeto-Burmans and Indo-Aryans in consecutive waves of migration. Archaeological evidence confirms that by the second millennium BCE, rice-cultivating communities inhabited the region.
By the 11th century people lived in systemically-aligned housing, buried their dead, manufactured copper ornaments and black and red pottery. The Ganges and Meghna rivers were natural arteries for communication and transportation, estuaries on the Bay of Bengal permit